Carter Reardon is immensely likable as Stephen, the well-meaning architect who is the protagonist of "Eastern Standard," Richard Greenberg's satire on a bunch of yups who take a bag lady into their Hamptons beach cottage. Reardon's height, beard and longish dark hair give him an archaically dashing look, but his Stephen is diffident, even humble. He is a man who can bring an earnest, meditative quality to the act of munching on a bread stick. Playing Stephen as so serious that you have to laugh at him yet so decent that you have to take him seriously, Reardon makes the character the bashful but strong heart of Greenberg's clever, shallow little comedy, now at the Source Theatre.

Reardon heads a pleasant and attractive cast, all of whom play with enough looseness to rumple the neat flat surfaces of the script. In its New York production, "Eastern Standard" was directed so slickly you could slip on it, and it had an all-too-knowing air. Greenberg is very talented in a facile way -- he writes on the level of superior TV drama such as "thirtysomething," and he has a gag writer's gift for one-liners. But his characters are all the same: intelligent and/or quirky, and exhaustingly articulate. They don't do anything, they just tell you their attitudes. They often tell you very amusingly -- a painter refers to his contemporaries as "the cutting edge of the passe" -- but the effect is still of bright empty chatter, of Greenberg's witticisms reflecting one back on another in an endless repetitive pattern.

The pattern neatly contains three couples: Stephen and the ex-Wall Streeter he falls for, Phoebe; Phoebe's brother, Peter, a one-time heartbreaker now ill with AIDS, whom Stephen's old friend Drew falls for; and two misfits, Ellen, a spacey waitress, and May Logan, the bag lady. All these characters meet in the restaurant-set first act, which is a superb light-comedy minuet of manners. Yuppies aren't exactly the hardest satirical target to hit; still, Greenberg -- inventing dishes like "grouper tortellini," or having Drew hail the waitress with the cry, "Oh actress!" -- definitely scores his points. The actors toss the wisecracks around like balls, and the play is giddy and fun.

Then Greenberg moves the action to the beach and promptly goes in over his head. Peter trudges around stoically keeping his terrible secret. In case we don't appreciate how brave he is, Phoebe is there to cue us: "You don't tell anybody," she says to Peter with admiring sympathy. "How can you stand it?" (This play isn't set in the ordinary petty world where we lesser mortals live -- where the dying might keep their plight secret not to spare others but from the simple selfish desire to live a normal life for as long as possible.) Rick Foucheux is too smart to play the role smiling through tears, but Peter is a real smiling-through-tears part: plucky as all get-out.

While Peter and Drew have their bittersweet romance, May, on medication for schizophrenia, putters around and takes care of everyone. She turns out to be a wonderful cook. Naturally, the heartless privileged folk patronize her and then let her down -- although what they could do about her illness is unclear. Greenberg seems to think that providing affordable housing and dealing with the plight of the mentally ill are the same problem. And his May is your usual stage Crazy Person: Though mad, she is not as foolish as her hosts. "Eastern Standard" may be set in the '80s, but its cliches are right out of the 19th century.

The actors sink the cliches as much as they can. Cam Magee, a gifted eccentric actress, is both daffy and touching as May. Husky-voiced and wary, she's clearly a woman who's been roughed up by life, yet the experience has left her as bewildered as angry. The wittiest, bitchiest lines in the play belong to Drew. Kevin Reese not only gives them the delivery they deserve, but also brings a surprisingly convincing romantic ardor to his wooing. Brilane Bowman is both sweetly soft and obnoxious as Ellen, and Kimberly Schraf blunts Phoebe's career-woman edges (these women are never anything but hard-edged) with a goofy, slightly lost quality. Foucheux carries his martyrdom around without getting on our nerves and is very appealing when he's silly or vain.

On Tom Meyer's airy, elegant set, the director, Joe Banno, keeps what action there is sprightly. He plays up "Eastern Standard's" strong elements -- its jokes and charm -- and doesn't fuss too much with its ill-dramatized "themes" of middle-class insularity and selfishness.

In Jean Renoir's film "Boudu Saved From Drowning," a householder rescues an indigent and then tries to inculcate him with "proper" bourgeois values. In Luis Bunuel's savage movie "Viridiana," a man releases a mistreated dog tied to a cart, only to pass a few minutes later another poor dog in exactly the same situation. But Greenberg doesn't show his people as smug in their values (their worst fault is a rather innocent insensitivity) or mock the uselessness of their efforts. At play's end, Stephen is planning to build "housing for the homeless," and through Drew makes fun of his liberal do-goodness, it's the only political option Greenberg offers.

Greenberg read all the right plays in graduate school. That beach house in the Hamptons where the privileged parade their aimlessness is Chekhov's house -- the dacha in "The Cherry Orchard" -- and Shaw's Heartbreak House as well. It's also Shakespeare's Arcadia, that away-from-the-city setting where lovers find each other. At the end of "Eastern Standard," the troublesome May is gone but the lovers have united. Like the final scene of "The Merchant of Venice," where we're supposed to forget Shylock's suffering and rejoice with the happy couples, "Eastern Standard's" ending is sour, a fake. Greenberg raises real problems, and then can't deal with them any better than the characters he satirizes.

Eastern Standard, by Richard Greenberg. Directed by Joe Banno. Set by Tom Meyer. Lights by Jennifer Garrett. Costumes by Thomas W. Mallen. Sound by Robin Heath. With Carter Reardon, Kevin Reese, Brilane Bowman, Kimberly Schraf, Rick Foucheux and Cam Magee. At the Source Theatre, 1835 14th St. NW, through Feb. 16.